Jamie remembers that he doesn't have a circle; he just orbits other people's.
But the point about Thea is that she's strictly a behind-the-camera girl. She wants to see, not be seen. No one's really ever understood that about her.
Paul knows he shouldn't really have bothered telling her anything about himself. She's the kind of girl who takes part in those ridiculous discussions where you have to provide a punchline at the end of everything you say, every anecdote you tell. If anything ordinary happens, or sad, or tame, it's just not good enough. The end always has to be funny.